Fuel system



May 27,193o-f E.' Q. ENGLS UEL SYSTEM FOR INCLosED BURNER BAKE ovENs `2 Slrtuaets--Sheet l Filed Nov.8', 1928 far/Ar IN VEN TOR CAI? EWGEZS' v ATTORNEY May 27, 1930 E. o. ENGELS 1,760,48@ I FUEL SYSTEM FOR- INCLOSED BURNER BAKE OVENSy I Filed Nov. 8, 1928 2 sheets-sheet 2` EUGENE QSCAR EVGELS A TTORNE Y Patented May 27, 1930 incase erre Ene-ENE oscAE EneELs', er sAsinAw, MicirreAn, Assis-non To BAKER `PERKINS cOMPANY, inc., or sAsrnAw, MICHIGAN, A conroEAlrion or NEW YOEK EUEL sYs'rEia EdEincnesnn-Bnnnna BAKE OvENs Y Application led- November 8, 1928. Serial No. 317,943.

`plied in this invention possesses several im portantadvantagesover the open. flame burners. Neither its iamenor the products of combustion can Contact with the loaf-conditioning steam; less steam is required to maintain a satisfactorily wet atmosphere and the burner llame is unaffected by steam and vapors released from the loaves being baked. Economical flames `can i be maintained throughout all heated Zones. of the oven and no soot or undesirable gases can get into the oven from the burners, regardless of variaf tions in the quality Vof the oven atmosphere.

This invention provides eXtreme fiexibility for variety baking because of the ease with which its heat Zones and burner distributions Vcan. be adjusted, altered and adapted to various requirements of operation. j ln its more specific aspects the present imjirovements pertain to the mounting of the burners, and the arrangement, construction and` mode of operation of the burner jackets, the fuel supply headers, thespent gas or exhaust headers, themeans for deliveringl gas air mixture 'to theburner and means for ig niting, regulating and inspecting` the iame, and means for conducting away the spent gases. j

i The inventive ideas are embodied in gas control and prehcating1 `devices concealed within the wall structure ofthe oven and so arrangedas to prevent heat conduction from the baking chamber to points outside the oven. rllhe outside walls are,'t;herefore, smooth, unobstructed byfittingsand in appearance most attractive; l i n j l/Vith the foregoing and certain other objects in view, which will appear later in the specification, my invention comprises the devices described and claimed and the equiva lents thereof. i j

ln the drawings Fig. l is a part sectional view on the line 1 1 of Fig. 2 of a portion of the oven wall and a portion of the top or crown of the oven, showing two heating ele ments and their relation tothe claimed features of the invention.

Fig. 2 is a fragmentary plan view, partly in horizontal section, of the parts shown in Fig. l, the sectional part taken on line 2-2 of Fig. 3, the intake header being removed.

Fig. 3 is a front view of the adjustable slidable panel for the baking chamber wall, showing the relative locations of the intake housing,` the spent gas exhaust housing andthe connections to the intake and exhaust headers. Fig. l is a diagrammatic detail view, partly in section, of the panel, burner and burner jacket arrangement. j

lin the'embediment of my invention shown herein, the tubular gas burner l is received in an outer tubular jacket 9. ofsubstantially `lJ-form, its ends disposed side by side, constituting' theso-called indirect-heat arrangement. l Both ends of the Ll-shaped burner jacket terminate at an apertured plate or `panel 3 adapted to be applied as an integral part of the baking chamber wall d or to be detached therefrom and shifted to a different place along the wall as'indioated in dotted lines in Figsj?) and 4,-in order to bring about changes in the .heat distribution `by rearrang ing' the burners. This novelburner enclosure and apertured panel arrangement enables the entire combustion system to `be cleaned easily and quickly. lts arrangement is such that even if an explosive flasheback should occur within the jacket in the limited space around the burners it can do no damage, because of the relatively small volume'of gas involved.

rlhe fuel supply or intake header is in this invention preferably` built up lof individual lengths or sections 5` of pipe arrano'ed endto-end. It is disposed adjacentthe wallft of thebaking chamber and is heated `therefrom. i i f `The means for supplying fuel from the intake header to the burner 1 is a .gasfair conduit V6.` This" conduit is preferably, cast integral with a fuel intake housing 7 on the shiftable panel 3 of the baking chamber wall.

An end of the gas-air intake conduit is shaped to fit around and releasably embrace the intake header, and is shiftable to any desired location along the length of the header. For that purpose a packing gland 8 is preferably employed constituting a connecting fitting between the end-to-end sections 5 of the intake header. The gland is provided with means for keeping the ends of the two tubes separated, preferably a bolt 9 that projects radially into the cylindrical barrel of thev land and forms a stop between the ends of t e tubes so they can not be shoved close Y enough together to throttle the gas on its way from the intake header to the burner.

The exhaust or spent gas header likewise is disposed in the space between the outer wall of the oven and the wall of the baking chamber and lies adjacent the latter, so as to utilize otherwise waste heat for reducing radiation losses from the chamber, and improving the fuel economy of the oven by preheating the gas-air fuel mixture just before it reaches the burners and also preventing harmful expansion and contraction of the exterior paneling 10 which is commonly made of glass, tile or other brittle material.

Spent gases from the burner jacket dass through an outlet or exhaust housing, in the form of a hollow casting 11, which is attached to the panel 3 alongside the fuel intake housing 7. This housing 11 communicates with a conduit 12 that connects with the spent gas exhaust header. An end 13 of this spent-gas conduit 12 is shaped to fit and releasably em brace the spent gas header at any desired location along the length of the header. The intake and spent gas headers extend in the same direction, preferably parallel. The Vintake housing 7 and the exhaust outlet housing 11 can be used in the positions shown in the drawings, or they may be inverted, depending upon whether the corresponding header is above or below the panel 3. p

` The paneled outer wall of the oven is formed with an aperture 14 opposite the shiftable panel 3, and the aperture is normally closed by a plate 15 through which prothe regulating, ignition and flame-inspection devices, namely the stem 16 of the fuel valve that controls the rate of flow of fuel gas from the' intake header to the burner, the end of the usual electric ignition device 17, and the custom ary inspection eye-piece 18. Y The ignition device "is of usual form, generall consisting of a tubular spark plug withl spar points 17r at its inner end and wiring yterminals 17 atits outer end. Y

iThe `burner inspection device consists of a tube 18 directed into the burner jacket and having at its outer end a glass cover 18a for the protection Y, of the observers eye. The glass 18a-is mounted in a vertical slide 18b by which the glass can be put into or out of register with the end of the tube.

A wall of heat-insulating material such as blocks or slabs of magnesia or asbestos is builtup between the outer oven wall and the wall of the baking chamber. In conjunction with the concealed hot spent gas header and its conduits 12 there is provided a novel means for preventing accumulation of water of condensation within the wall of insulating material or upon the inner faces of the exterior oven wallpanels 10. To that end the insulating material, with the spent gas header, its conduits 12 and housings 11 concealed therein, is spaced apart, as at X, from the outer paneling 10 and in the air duct so made a slow but constant air circulation is induced by the heat of the exhaust gases. Air enters through openings 10 at the lower margin of the wall, passes upward between the inner face of the paneling and the insulating material, taking up moisture and escaping to the atmosphere near the top of the oven wall at 10", thereby protecting panels 10 of the outer wall against cracking by heat changes.

Heretofore it has been the customary practice to place the intake headers and their associated Y fuel conduits to the f various burners, outside the oven and they have usually been painted or enameled. In the event of explosive back-firing the paint or enamel was sometimes scorched, the oven wall was smoked and unpleasant odors developed. In my improvement these objections are overcome because the intake pipe, being hidden within the oven wall, requires no paint or enamel and consequently inadvertent backfiring in the burner can do no injury to the appearance of the oven.

The mode of operation of the invention is as follows:

Gas-air mixture from the intake header flows through the conduit 6, regulating valve and housing 7 to burner 1. Spark plug 17a lights the burner, and the gases of combustion escape from jacket 2 through apertured panel 3, spent gas housing 11, conduit 12 and the exhaust header.

The incoming fuel is preheated on its way to the burner by reason of the proximity of the intake header, its conduit and its housing, to the hot spent gas header and baking chamber wall 4.

The hot spent gases in their passage from the burner keep the baking chamber wall 4 heated to a suflicient degree to practically eliminate loss of baking heat by radiation or conduction, because of reduction of the temperature dil'erence between inside and outside. Furthermore, the'heat insulating wall 3i is keptfree from moisture, and a slight upward draft is established in wall duct X, keeping the outer paneling 10 at a uniform temperature.

Regulation of the gas ames is had by the iastate valve handle "16 and inspection "is made throughthe peep tube 18.

`lfthelbiirnersrequireto be shifted as indicateddiagrammaticallyin Figs. 3 and 4, to bring abolita -redistribution of heat in the baking chamber or in the loafsteaming dejpartmentofthe oven, the plate 15 in the outer wall is loosened and an adjacent panel freinoved. The panel 3 of the bakingchaniber wall is then loosened, the connections 8, 13 between the ends of conduits 6, 312 and the A"intake and Vexhaust headers are released, and

` the panel together with its attached burner 1, jacket'2, and intake and exhaust housings i between burners.

7, 11 canbe shifted bodily to any other defsiredposition onthe baking chamber wall, in fthe manner set forth in my co-pending application Serial No. 312,288. y

For connecting up the intakelieader at the "new burner position lpipe sections are selected of Vlengths suited 'to the new distance Their ends are inserted into the packing `gland 8V and against the "fio 'abutment 9.

y The `eicha'irst headeris apertured at a place registering with 'the end ofthe exhaust conduit 13 `in its new position, and then the panel V3 `and the ends Vof the conduits 6, l2 are scciued in place, after which the heat-insulating wall is built uparound the burner and panel 3, theplate 15 ofthe outer wall `is secured in place and flanked by newly litted outer wall panels 10, `preferably applied as described -in my' "co-pending application, Se-

rial No. 312,239,1iledv October 13, 1923.`

'1t maybe repeated at this point that there is a novelinode of operation of the burners andassociatedparts, and anovel cooperative fiel'ationship between the indirect-heat type of burner'employed in conjunction with the shiftable panel andthe gasprelieating, heatsavingand walltemperature stabilizing feaitures ofthe intakeand spent-gas headerai1- rangements. The factors that make the inclosed U-type panel-mounted burner an `im- Qportant part of the invention as claimed may belnted.

For the "purpose of this invention the in- "closedtype burner `herein describedpossesses "important and novel operative advantages over *the usual `open flame type burner that become apparent from` the followingcom-- parison: Y 1

y An open flame burner located in tliesteam* .gpm-ying C Ompartment of anoven requires more voxygen than one remote from the steaming zone. Hence two open llame burners can not be satisfactorily connected to the same gas-air mixer. As a further example,

the blaze of anopen flame burner situated" just inside the unloading end of an oven encounters varying amounts of atmospheric oxygen driven in from outside and it is al most impossible to maintain a proper gas-air i 'A `mixture throughout the oven, especially if the usual 'unit 1preoiiixiiig system` is lu'sed. Moreover, open lamefburners tend to dry out Iand overheat the loaf-conditioning steam `in the baking chamber, requiring more steam to be added in order `to maintain la 4saturated atmosphere, thus complicating the problems of oven heat control.

`My `invention as herein described avoids the diiiicultiesassociated with open burners and in addition makes itpossibleto produce `an oven all of whose fuel gas and exhaust coniiectionsare out of sight, leaving a smooth handsomely finished tile,"glazed or enameled oven wall, yet possessing alltlie advai'itages setforth inthe foregoingstatements yof the invention. 1

y "Having thus described my invention, what I claim and desire to secure by Letters i 1.*In combinatiomawalledovemanindependently walled baking chamber therein, a

tubular gas `burner having an "enclosing Jacket of substantially Ulform, its ends 4disposed side-by-side, an Aadjustably shiftable panel normally constituting an integral lpart of a wallof saidchaniber,said `panel 'formedl with apertures in register with the ends of said jacket, for the purposes set forth.

2. ln eombinatioma walledoven', an independently walled bakingchamber therein, a tubular gas burner 'having an enclosing Vjacket ofsubstantially U-form, its ends disposed side-by-side, an adjustably slii'ftable panel normally constituting an integralp'art of a wall of said chamber, said 'panel kformed with apertures in register with theend's "of saidjacket, the outer wall oftheovenforined with an aperture `opposite said sliiftabl'e panel, for affording access tosaidpaneland fintakeheader adaptedto be preheated from said wall,theehaustlieader iadapted `to impart heat thereto, andy gas conduits connecting each heatingelement `with saidlie'aders.

4. A walled outer ovenstruoture, a baking f chamber contained therein whose side walls are in spaced relation th'ereto,a heatingelement of the inclosed burner type within the baking chamber comprising a tubular jacket anda tubular burner therein, a fuel intake header `disposed adjacent awalllof thebaking chamber adapted to beheated from said` wall, and conduit connecting said burn-v er 'with said header, andmeans `for removing spent 4gasesffrom saidjacketffr 'the rpur-V poses set forth. i A i '5. A walledouteroven structure, "affbaking chainbercont'ained therein whose side `walls are in spaced relation thereto, a heating element of the inclosed burner type within the baking chamber lcomprising a tubular jacket and a tubular burner thereina spent gas .exhaust header disposed adjacent a Wall of lthe baking chamber adapted to impart heat thereto, a spent gas conduit connecting said jacket ywith said exhaust header and means for supplying fuel to said burner, for the purposes set forth.

6. In combination with the baking chamlber of an oven, a fuel intake header and a spent gas header arranged parallel, a shiftva le panel normally constituting an integral part of a wall of said chamber, a U-shaped eating element projecting from a face of said panel and comprising a tubular burner lnd an enclosing jacket, said panel carrying 4on its other face a fuel intake control valve,

a cnduitconnecting the fuel intake header with said valve and a conduit connecting said burner jacket with said spentgas header, for the purposes set forth. 4

v7. ,A structure as defined in claim 6 wherein the ends of the conduits are shaped to `releasably embrace respectively the intake header and the exhaust header at any desired location along the length of said headers.

8. In combination with a baking chamber lof an oven, a fuel supply header and a spent gas header extending in the same direction, a heating element operably associated with a panel that normally constitutes an integral part of a `wall of said chamber, said panel carrying a fuel control valve and a conduit member connecting the fuel supply header with said valve and a conduit member connecting saidheating element with said spent gas header, for the purposes set forth.

housing on said panel, a conduit integral with `said second housing and connecting with the spent gas header, an end of said last-mentioned conduit shaped to.V fit and embrace the spent Y gas header, for lthe )ur osesset forth. Y

10. In an oven oft e c ass described a panel having a heating element Aof the gasfired .type mounted thereon, an intake housing and a spent gas housing arranged on said panel, communicating respectively with the burner intake endand the'spent gas exhaust end of said heating element, each housing adapted for inversionwith respect to said panel, and intake-and exhaust headers communicating posed of a plurality of tubes arranged endi to-end, a packing gland arranged to receive ends of two adjacent tubes, said gland communicating with one of said housings, and

means associated with the glad for constraining the ends of said tubes therein to spaced relationship.

12. In a bake oven having an outer wall and an inner baking chamber wall spaced apart, a removable apertured panel of said inner wall secured to an inclosed-type burner that .projects from a face of said panel into the baking chamber, a fuel-intake housing and a spent-gas outlet housing also secured to they panel, both housings projecting from the face of said panel opposite said burner intothe space between said walls, for the purposes set forth.

13. In a bake oven, a paneled outer oven wall, a baking chamber Wall in spaced relation therewith, a wall of heat-insulating material between said outer and baking chamber walls and spaced from said outer Wall, providing an air-circulating duct behind the panels thereof, and a heated spent-gas header in the space between said Walls and inclosed by said insulating material, for the purposes V set forth.

14. A structure as defined in claim 12 wherein the intake housing carries a fuel intake control valve, an ignition device and burner inspection device, all operable from outside the outer Wall of the oven.

15. A baking chamber, a removable apertured panel of a wall thereof secured to an inclosed-type gas burning element that projects into the baking chamber, a fuel-intake housing and also a spent-gas outlethousing secured to the face of the panel opposite said burner, for the purposes set forth.

16. A Walled outer oven structure, a baking chamber contained therein whose side Walls are in spaced relation thereto, a fuel burner inclosed within a jacket and located Within the baking chamber, a fuel intake conduit connected to said burner and an eX- haust lconduit connected to said jacket both of said conduits disposedvin the space between said Walls and located in proximity to each other ,for heat interchanging.

In testimony whereof, I ailiX my signature.

EUGENE OSCAR ENGELS. 

